Throughout sub-Saharan Africa, adolescent girls and young women engage in risky sexual behaviors that lead to poor reproductive and sexual health outcomes. The period from adolescence to early adulthood is characterized by the formation, evolution, and dissolution of diverse types of relationships with male partners from one-time encounters to marital unions coinciding with similarly complex changes in sexual behaviors and risk. Survey data on sexual behaviors within these diverse partnerships tend to be quite limited, however, and continue to suffer from measurement error, including recall and social desirability biases. New data collection approaches are urgently needed to improve both the scope and the quality of these data, and this application will test two innovative methods to meet these aims: First, a matched partner data set will be created by interviewing a random sample of women (aged 18-24) and men (aged 18-29) in Kisumu, Kenya, and by refining a strategy to recruit and interview their recent (in the last year) marital and non-marital sexual partners. The feasibility of this strategy will be assessed as well as the extent and type of selection bias with respect to which partners ultimately participate in the study. Is a larger and less biased sample of couples obtained by recruiting partners through women or through men? Second, a new survey method, the Relationship History Calendar (RHC), will be designed, which collects detailed, retrospective data on the romantic and sexual relationships of female and male respondents for up to 10 years prior to the survey. Both the structure of the questions and the interview process of the RHC are designed to minimize recall and social desirability biases. Respondents and their matched sexual partners will be randomly assigned to receive the experimental RHC instrument or a comparison standard Sexual Partnership Questionnaire (SPQ), such as the one used in the Demographic and Health Surveys, thereby allowing the assessment across instrument type and by sex of respondents. The feasibility and acceptability of the RHC compared to the SPQ will be assessed. The quality of sexual behavior data obtained from the RHC compared to that of the SPQ will also be evaluated. The ultimate goal of the proposal is to provide researchers with proven methods to collect highly contextualized, time-varying data. These data can be analyzed to understand how relationship histories and couple dynamics affect the sexual risk behaviors and extremely poor reproductive health outcomes of young women and men in sub-Saharan Africa. [unreadable] [unreadable] [unreadable] [unreadable] [unreadable]